I had a miscarriage before and the same thing happened to me go to the hospital asap.
I had a miscarriage when I was about 6 weeks too, bled for a week, then had intercourse and got pregnant again.. im now 8 weeks pregnant and everything is good so far. Your body was cleaning itself through bleeding, it probably temporarily stopped but when you had sex it rushed more blood down.. unless bleeding doesn't stop after a week, you should be fine.. if it's more than a week, see a doctor